The present invention relates to electronic clock circuitry for a clock having chimes or an alarm system, or both, for the production of a sequence of tone signals.
Clocks with chimes produce sequences of acoustic tone signals every quarter, half, three quarter and full hour. These acoustic signals can be individual single tones or short melodic sequences. The tone signals are generally produced by mechanical means. Electric alarm clocks produce a tone signal by means of a separate generator at specifically set times. Musical alarm clocks can also turn on a program of a radio station by activating a radio at a specifically set time.
A number of different electronic clock circuits are known which are formed as integrated circuit chips (see for example H. Bernstein's article "Beispiele integrierter Schaltungen," at pages 122 and following). These known electronic clock circuits are not suitable for the storage and production of tone signal sequences, for example short melodies. At best, they include a switchable output terminal which can be connected to a separate tone generator.
It is an object of the present invention to provide an electronic clock circuit which is suitable for the storage and production of tone signal sequences, such as strokes or short melodies produced on the hour.
The present invention achieves this objective by providing a novel clock circuit in which data pertaining to at least one sequence of tone signals, such as tone frequencies and tone lengths, is stored in digital form in a memory circuit. The data pertaining to the sequence of tone signals, or pertaining to individual sequences of tone signals, is recalled from the memory circuit at a certain time, and the recalled data is translated into the desired tone signals by means of an electroacoustic transducer, such as a loudspeaker. Depending on the storage capability available with the memory circuit being utilized and the amount of data for the tone signal sequence to be stored, it is possible to store one or more sequences of tone signals which can be recalled at various designated moments in time, or at any other desired time.
In a further aspect of the present invention, the recall of the data relating to a tone signal sequence can be accomplished by means of a switch which is controlled by the clockwork mechanism of the clock. In another development of the present invention, a time counting circuit can be incorporated in the clock circuit, and this circuit can be programmed to recall the stored data at a specific moment in time. The clock circuitry can be assembled with microprocessor and memory modules which are well known. Such integrated circuit systems are commercially available and are described, for example, in the publications by Werner DIEHL, "Mikroprozessoren and Mikrocomputer," Wuerzburg, 1977 and by H. PELKA, "Von der Schaltalgebra zum Mikroprozessor," Muenchen, 1977.
In a further development of the present invention, a sound producing network, such as a resonant circuit, is placed in series with the electroacoustic transducer, thus making it possible to influence the sound of the tone signal sequence.
The electronic clock circuitry proposed by the invention can be used in connection with various modes and conditions. The clock circuitry provides a clock with chimes or an alarm system where the form of the tone signal sequences can be programmed. It is further possible in cases where a date function is present to produce a special tone signal sequence for a specific date.
Additional advantageous developments of the invention will become apparent from the description given below.